Many structures, for example, hoses, condoms, gloves, cannulas, catheters, and the like, are made of a polymeric material (e.g., latex, silicone). Such polymeric structures may have various shapes, e.g., sections with different diameters, contours, etc. In addition, various cavities might be present in the structures, some of which might contain fluids of various types. A traditional way to form such structures is by adhesively affixing parts together so that the outer coat can attain the desired shape. However, these traditional methods do not lend themselves to mass production and are labor intensive. Some shapes are extremely difficult if not impossible to make by traditional adhesive methods. likewise, traditional methods of making shaped structures of nonpolymeric substances, such as inorganic materials, with cavities therein sometimes have similar difficulties.
An example of a shaped polymeric structure is a catheter. Most catheters are cannulas or tube like devices which are inserted into a portion of a person's body in order to transport fluids, such as liquids, gases, and sometimes semisolid material, in or out of that particular portion of the body. For instances, urinary catheters are used to transport urine collected in the bladder out of the body via the urinary tract. Other types of catheters such as gastronomy devices, transport fluids into and out of various segments of the gastrointestinal system, primarily the stomach.
In order to provide a means of retaining the catheter within the body, inflatable bag catheters were introduced many years ago. Subsequently, Foley (U.S. Pat. No. 3,409,016) taught an elongated catheter having a secondary lumen for inflating a retention balloon at a distal end of the catheter once the distal end is positioned within the body. Generally, the "distal end" is the end of the catheter that is first introduced into the body when the catheter is being positioned within the body and the "proximal end" is the end opposite the distal end. Such catheters are now generally referred to as "Foley" catheters out of respect for the contribution made by Dr. Foley. Because of the variation in needs of patients, improvements on Dr. Foley's contribution to the catheter art are continually being made. These improvements sometimes result in cannulas or catheters that have shapes quite different from that of the device originally designed by Dr. Foley.
Traditionally, Foley catheters are made by a process which includes slipping a band of cured rubber over a double lumen latex rubber tubing and affixing the band on the double lumen tubing by dipping the band and the tubing in a suspension of latex to form an outer layer. The cost of manufacturing traditional Foley catheters has been influenced by the need to use a significant amount of hand labor to make the devices, especially the silicone rubber Foley catheters. Moreover, in many cases where a polymeric structure such as a catheter is to have a cavity filled with fluid, traditional manufacturing methods can not be used. It will be appreciated that using such traditional methods to make catheters that have a variety of shapes and sizes of cavities between the tubing and the outer layer would add significantly to the cost of production and pose limitations on the variety of catheters that can be made. Reducing the amount of hand labor in the manufacture of such devices may reduce the cost of such devices so as to provide a more affordable product to the consumer and to render such a product more competitive in the market place.
The same problem of high labor cost and limitation of the variety of shapes is similarly encountered in the manufacture of other shaped structures such as gastronomy devices, condom, and hoses. The present invention provides a method of making polymeric structures which offers substantial advantages over traditional manufacturing methods. In addition, the present invention provides a simple, easily applied, comfortable disposable catheter for incontinent females.